R31A6-0-03

Briefing:

You try to start a multiplayer session, host or join an online quest, and get the error "Failed to create session. R31A6-0-0:3."

Likely Cause:

A network connectivity issue preventing the game from establishing the multiplayer session. The cause can vary and may involve region, NAT type, or IPv6 routing and firewall rules.

Prerequisite:

Check if the servers are actually down.

Before troubleshooting your own network, check the official Monster Hunter status account at @MHStatusUpdates. If they are reporting a widespread outage or maintenance, the issue is on Capcom's end and no local fix will work. Wait for the servers to come back online.

General Fixes (try in order):

1. Restart your router.

Turn it off, wait 30 seconds (so it fully powers down and clears cached connections), then turn it back on.

2. Check your NAT type.

There are three main NAT types. Open/Moderate/Strict, respectively 1/2/3 on Playstation. A Strict NAT type (3) may interfere with multiplayer connectivity. To check your NAT type:

PlayStation: Settings → Network → View Connection Status → NAT Type

Xbox: Settings → General → Network settings → Test NAT type

PC: Visit CheckMyNAT and click Detect NAT. If it shows you Symmetric NAT, that's type 3, and may handicap multiplayer connectivity. You can remedy this by accessing your router's admin page. Learn how in How to Access your Router's Admin Page.

After you enter your router's admin page, you will have to find Universal Plug and Play (UPnP), which is usually found under sections such as "NAT," "Port Forwarding," or "Advanced," and enable it.

Note: While a possible fix, UPnP has a known security trade-off. It lets devices on your network open ports automatically. For most home users, the difference is negligible. If you're security-conscious or on a shared network you're wary of (like a campus's,) you can skip UPnP and manually forward the ports instead. To manually forward the ports, visit Manual Port Forwarding.

If your NAT type is 1 or 2, or you enabled UPnP or manually forwarded the ports and the problem persists, continue reading.

3. Disable IPv6.

Some networks may have IPv6 routing problems that do not affect IPv4. Disabling IPv6 forces the device to use IPv4 instead. This has no bearing on latency or lag.

On PC:

On Playstation and Xbox:

You will have to disable IPv6 through your router's admin page. Note that not all routers have such an option. If you wish to try, visit How to Disable IPv6 for Consoles. If you would like to try other steps first, continue reading.

4. Disable Crossplay.

This is especially relevant in certain countries with regional restrictions or limitations, but means losing the ability to play with different platform users. In Monster Hunter Wilds, this will also mean that you can only play with those who have their own Crossplay setting disabled.

To disable it:

If you need Crossplay on, continue reading.

5. PC only. Change Virtual Private Network (VPN) status.

Some countries, like Egypt, encounter this error due to regional limitations. The game may treat connections differently based on their IP address or geographic origin. First, if you have a VPN enabled, try disabling it and see if that resolves the error. If it does not:

If the error results because of how data is routed from your device to the game's servers, a VPN like Cloudflare's WARP changes that route, possibly resolving the issue. If you wish to try Cloudflare's WARP, you will need to download the application at 1.1.1.1.

After installing 1.1.1.1:

Note: If the error is related to how your connection is treated based on your geographic origin, then trying a VPN that makes it seem like you're connecting from a different country may bypass that. Cloudflare does not achieve that, but a more conventional VPN does. If you wish to test whether this is the case, I recommend trying Proton VPN, as it has unlimited data on its free plan.

6. PC only. Change network profile from public to private.

Low-confidence fix. A public network profile has stricter firewall rules than a private one. If such rules were the cause behind the error, a more lax private profile may work.

To do so:

If none of these fixes work:

The problem might be outside your control. It could be an issue with Capcom's multiplayer infrastructure or your ISP's routing. If the steps above did not resolve the issue, you can try reporting the problem to Capcom Support by filling out their technical inquiry contact form. Include your platform, region, ISP, error code, and the troubleshooting steps you already tried.